It should be in the fuel line near the front of the motor ( If I remember correctly) Should be a tuna can sized device with the fuel lines to it.
1985 F150 XLT Lariat 5.8L (351w) HO, "Holly built for Motorcraft" 4bbl, C6 Transmission, 4X2 extended cab, 8 foot bed.
"Some people spend a lifetime wondering if they've made a difference, Marines don't have that problem." President Ronald Regan 1985. I think he should have ended with: "Veterans don't have that problem." But that's me. D.A.V. USAF 1976-1992.